
\begin{tikzpicture}[scale=4]
  \coordinate[label=below:$C$] (C) at (0,0);
  \coordinate[label=below:$A$] (A) at (4/3,0);
  \coordinate[label=left:$B$] (B) at (0,2);
  \coordinate[label=left:$D$] (D) at (0,2/3);
  \coordinate[label=right:$E$] (E) at ($ (B)!(D)!(A) $);
  \pic[mark angle={teal}{3mm}{1}] {right angle=A--C--B};
  \pic[mark angle={teal}{3mm}{1}] {right angle=B--E--D};
  \draw (A) -- (B) -- (C) -- cycle (D) -- (E);
  \draw[red] (C) -- (E);
  \draw[green] (A) -- (C) (B) -- (D);
\end{tikzpicture}
